Export class instead of several functions

index.js

@@ -14,15 +14,20 @@ const gerberFiles = [
   'CAMOutputs/GerberFiles/profile.gbr',
 ];
 
-/**
- * Configures the folders used
- * @param {Object} folderConfig Object with properties tmpDir and imgDir containing paths to temporary and image output folders
- */
-function config(folderConfig) {
-  // Create tmpDir if it does not exist
-  fs.ensureDirSync(folderConfig.tmpDir);
-  // Create imgDir if it does not exist
-  fs.ensureDirSync(folderConfig.imgDir);
+class ImageGenerator {
+  constructor(folderConfig, imgConfig) {
+    // this.folderConfig = folderConfig;
+    this.tmpDir = folderConfig.tmpDir;
+    this.imgDir = folderConfig.imgDir;
+    this.imgConfig = imgConfig;
+
+    // Ensure that the folders exist
+    try {
+      fs.ensureDirSync(this.tmpDir);
+      fs.ensureDirSync(this.imgDir);
+    } catch (error) {
+      throw new Error(error);
+    }
   }
 
   /**
@@ -31,7 +36,7 @@ function config(folderConfig) {
    * @param {string} tmpDir Temporary directory to extract to
    * @returns {Promise} Promise object represents number of files extracted
    */
-function extractArchive(fileName, tmpDir) {
+  static extractArchive(fileName, tmpDir) {
     // Check archive exists
     try {
       if (!fs.existsSync(fileName)) {
@@ -53,7 +58,7 @@ function extractArchive(fileName, tmpDir) {
    * @param {string} dir Directory containing layer files
    * @returns {Array} Array of paths to the layers files
    */
-function getLayers(dir) {
+  static getLayers(dir) {
     return new Promise((resolve, reject) => {
       // Make sure the directory exists
       if (!fs.existsSync(dir)) {
@@ -78,7 +83,7 @@ function getLayers(dir) {
    * Clean up the archive folder in the specified directory
    * @param {string} dir Path to a directory to clean up
    */
-function cleanupFiles(dir) {
+  static cleanupFiles(dir) {
     try {
       const folder = path.join(dir, 'archive');
       fs.emptyDirSync(folder);
@@ -91,14 +96,12 @@ function cleanupFiles(dir) {
    * Take an archive containing gerber files, config object, temporary dir
    * and output dir and create a PNG image from the gerber in the output dir
    * @param {string} gerber Path to an archive file containing gerber
- * @param {Object} config Object containing sharp settings for resizeWidth, compLevel and density
- * @param {string} tmpDir Temporary directory to extract the archive to
- * @param {string} outputDir Directory to save the image to
+   * @returns {Promise.<string>} Promise to return path to image
    */
-function gerberToImage(gerber, imgConfig, tmpDir, outputDir) {
+  gerberToImage(gerber) {
     // Create output dir if it doesn't exist
     try {
-    fs.ensureDirSync(outputDir, 0o644);
+      fs.ensureDirSync(this.imgDir, 0o644);
     } catch (e) {
       throw new Error(e);
     }
@@ -108,10 +111,10 @@ function gerberToImage(gerber, imgConfig, tmpDir, outputDir) {
       if (!fs.existsSync(gerber)) {
         throw Error('Archive does not exist.');
       }
-    if (!fs.existsSync(tmpDir)) {
+      if (!fs.existsSync(this.tmpDir)) {
         throw Error('Temporary folder does not exist.');
       }
-    if (!fs.existsSync(outputDir)) {
+      if (!fs.existsSync(this.imgDir)) {
         throw Error('Output folder does not exist.');
       }
     } catch (e) {
@@ -120,33 +123,32 @@ function gerberToImage(gerber, imgConfig, tmpDir, outputDir) {
 
     // Set filenames
     const imageName = path.basename(gerber, '.zip');
-  const destFile = `${path.join(outputDir, imageName)}.png`;
+    const destFile = `${path.join(this.imgDir, imageName)}.png`;
 
     return new Promise((resolve, reject) => {
-    extractArchive(gerber, tmpDir);
-    getLayers(path.join(tmpDir, 'archive'))
+      ImageGenerator.extractArchive(gerber, this.tmpDir);
+      ImageGenerator.getLayers(path.join(this.tmpDir, 'archive'))
         .then(pcbStackup)
         .then((stackup) => {
-        sharp(Buffer.from(stackup.top.svg), { density: imgConfig.density })
-          .resize({ width: imgConfig.resizeWidth })
-          .png({ compressionLevel: imgConfig.compLevel })
+          sharp(Buffer.from(stackup.top.svg), {
+            density: this.imgConfig.density,
+          })
+            .resize({ width: this.imgConfig.resizeWidth })
+            .png({ compressionLevel: this.imgConfig.compLevel })
             .toFile(destFile);
         })
         .then(() => {
-        cleanupFiles(tmpDir);
+          ImageGenerator.cleanupFiles(this.tmpDir);
           resolve(destFile);
         })
         .catch((e) => {
-        cleanupFiles(tmpDir);
+          ImageGenerator.cleanupFiles(this.tmpDir);
           reject(new Error(e));
         });
     });
   }
+}
 
 module.exports = {
-  cleanupFiles,
-  getLayers,
-  extractArchive,
-  config,
-  gerberToImage,
+  ImageGenerator,
 };